Chromosome Deletion Outreach
Provides a comprehensive introduction, with illustrations, to chromosome abnormalities.

NLM: Trisomy 2
Information on Trisomy 2 from Jablonski's Multiple Congenital Anomaly/Mental Retardation (MCA/MR) Syndromes Database, National Institutes of Health (U.S.).

NLM: Trisomy 2p
Information on chromosome 2p duplication from Jablonski's Multiple Congenital Anomaly/Mental Retardation (MCA/MR) Syndromes Database, National Institutes of Health (U.S.).

NLM: Trisomy 2q
Information on chromosome 2q duplication from Jablonski's Multiple Congenital Anomaly/Mental Retardation (MCA/MR) Syndromes Database, National Institutes of Health (U.S.).

Unique - Rare Chromosome Disorder Support Group
Based in the UK, this nonprofit organization offers information about chromosomal disorders and a registry.